Valve for laboratory glassware

ABSTRACT

A valve including a tapered glass barrel having a fluid inlet and an outlet in the wall structure thereof, receiving a rotary fluorocarbon or equivalent plug having a handle portion by which it may be turned in the barrel on its axis, having a complementally tapered portion; the plug, or the plug and the barrel together, defining a fluid passageway between the inlet and outlet when the plug is in an angularly adjusted position thereof. The construction and arrangement of the elements may be such that flow of a liquid through the valve may be visually observed. The plug, which is formed of deformable material, is provided with an axial recess within the portion thereof which is received in the barrel and opening through the smaller tapered end of the plug, providing a relatively thin-walled portion of the plug. An elastomer insert is provided in the recess and a fastener unit is provided to maintain the elements in assembled position which unit comprises a threaded shank which in assembled position is secured to the plug extending axially thereof. The fastener unit also comprises a member co-acting with the shank, overlying the end of the barrel opposite the handle portion of the plug to prevent, with the taper of the barrel and the plug, axial dislocation of the plug. The last-named fastener member is provided with an axial extension to contact and compress the elastomer insert to force it radially against the axial wall of the aforementioned plug recess, thereby expanding the plug in an axial region thereof, which is relatively flexible, to form a tight fluid seal between the plug and the barrel. The plug has frictional contact with the barrel only over a portion of that part of the plug which is received in the barrel, so as to reduce resistance to turning of the plug in the barrel by the handle portion.

United States Patent [451 Oct. 17,1972

De Angelis [54] VALVE FOR LABORATORY GLASSWARE [72] Inventor: William M.De Angelis, Wilton,

Conn.

[73] Assigneez Daran Products, Inc., Norwalk Conn.

221 Filed: June23, 1970 21 'Appl.No.: 49,085

[52] U.S. Cl ..251/209, 251/309 [51] Int. Cl ..Fl6k 5/04 [58] Field ofSearch ..25 1/188, 209, 309, 155

[56] References Cited UNITED STATES PATENTS 3,142,474 7/1964 Nelson..251/309 3,305,211 2/1967 Phillips 251/209 X 3,475,002 9/1969 Phillips..251/209 X Primary Examiner-Harold W. Weakley Attorney-S. E. Rockwelland S. P. Tedesco [57] ABSTRACT A valve including a tapered glass barrelhaving a fluid inlet and an outlet in the wall structure thereof,receiving a rotary fluorocarbon or equivalent plug having a handleportion by which it may be turned in the barrel on its axis, having acomplementally tapered portion; the plug, or the plug and ,the barreltogether, defining a fluid passageway between the inlet and outlet whenthe plug is in an angularly adjusted position thereof. The constructionand arrangement of the elements may be such that flow of a liquidthrough the valve may be visually observed. The plug, which is formed ofdeformable material, is provided with an axial recess within the portionthereof which is received in the barrel and opening through the smallertapered end of the plug, providing a relatively thinwalled portion ofthe plug. An elastomer insert is provided in the recess and a fastenerunit is provided to maintain the elements in assembled position whichunit comprises a threaded shank which in assembled position is securedto the plug extending axially thereof. The fastener unit also comprisesa member co-acting withthe shank, overlying the end of the barrelopposite the handle portion of the plug to prevent, with the taper ofthe barrel and the plug, axial dislocation of the plug. The last-namedfastener member is provided with an axial extension to contact andcompress the elastomer insert to force it radially against the axialwall of the aforementioned plug recess, thereby expanding the plug in anaxial region thereof, which is relatively flexible, to form a tightfluid seal between the plug and the barrel. The plug has frictionalcontact with the barrel only over a portion of that part of the plugwhich is received in the barrel, so as to reduce, resistance to turningof the plug in the barrel by the handle portion.

11 Claims, 4 Drawing Figures VALVE FOR LABORATORY GLASSWARE BACKGROUNDOF THE INVENTION l Field of the Invention This invention relates'tovalves of the type employed in laboratory glassware, for example, forinterconnecting two or more fluid conduits.

2. Prior Art Valves for use with laboratory glassware are well known.The earliest valves were all glass. However, in more recent years valveshave been developed which utilize a glass barrel with a plastic plug,usually of a synthetic resin of the fluorocarbon type, such astetrafluoroethylene. Such valves have advantages over all-glass valves.However, they also have certain disadvantages. There have, for examplebeen difficulties with sealing and with friction. It is common to use atensioning nut to draw the plastic plug deeper into the tapered barrel.However, the cold flow properties of the resin make it tend to elongateand thereby reduce the sealing effect. One approach which has beenproposed for solving these problems makes use of a cylindrical, ratherthan a tapered, barrel. The plastic plug is quite elongated and isfilled with granular rubber whichis compressed by acompression insert.This forces the plug into tighter engagement with the barrel, improvingthe seal. However, the cylindrical construction has a number of problemsincluding the requirement for ribs to provide sealing and to reduce thefriction. In addition, the prior art valves tend to be somewhat complexand to have more parts than is desirable.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide a valve for laboratory glassware which is extremelycompact, has very few parts, provides an effective seal with reducedturning friction, and wherein liquid flow may be visible. Other objects,features, and advantages will be apparent from the followingdescription.

There is provided a valve for laboratory glassware including a glassbarrel having a conically tapered, smooth, inner surface and twointegral side arms, each defining a fluid passage communicating with theinterior of the barrel. A plastic plug is rotatably positioned withinthe barrel with at least a portion of its outer surface bearing againstthe inner surface of the barrel and having a matching taper. The outersurface of the plug defines a partially circumferential groove which ispositioned axially of the plug to interconnect in an angular position ofthe plug the fluid passages. The plug also includes a handle portionwhich extends from its largediameter end and one of the barrel, and anaxial recess which extends inwardly from its small-diameter end. Anannular, elastomeric insert is positioned in the recess. A fastener unitis provided to maintain the valve elements in assembled condition, whichincludes a member abutting the other end of the barrel and a threadedshank with which it cooperates and which is secured in the plug, thelast-mentioned member being threadedly adjustable in and out and havinga portion thereof for compressing the insert, thereby expanding the plugagainst the inner surface of the barrel to provide a fluid seal.

In the drawing:

FIG. Us a side elevational view of a valve of this invention, a portionthereof being broken away to illustrate its construction;

FIG. 2 is a cross-sectional view taken substantially along the line 2-2of FIG. 1',

FIG. 3 is a cross-sectional view taken substantially along the line 3--3of FIG. 1', and

FIG. 4 is a partially exploded perspective view of the rotatable portionof the valve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrated valve comprisesa glass barrel 10 shown by way of example with diametrically extendingtubular side arms 12, 14. The inner surface 16 of barrel relativelynarrow central portion 28 in direct frictional engagement with the innersurface 16 of the barrel. The central portion 28 defines a groove 30which extends circumferentially partially around the plug 24 to providecommunication between the ports 18, 20 in an angularly adjusted positionof the plug, the fluid channel between the ports 18, 20 being defined bythe plug and the barrel in the form shown by way of example.

In the illustrated embodiment, one end of groove 30 terminates in aV-shaped portion 32. Internally of plug 24 there is formed a cylindricalrecess 34 which extends axially inwardly from the small-diameter end,forming a relatively thin-walled portion of the plug which has somedegree of flexibility. From the bottom of the recess 34, as seen in FIG.2, there extends a smaller diameter axial bore 36 which intersects aradial bore 38 extending I through handle-receiving portion 26.

Positioned removably in radial bore 38 is an elongated, pin-type handle40 having a tapped opening 42 extending transversely therethrough andalignable with axial bore 36. An elastomeric annular insert 44 is snuglypositioned with recess 34. The-illustrated assembly is completed by ascrew fastener unit 46 having an elongated shank 48 which threadedlyengages handle 40, and enlarged head 50 which overlies the end of barrel10, and a compression shoulder 52 which lies within recess 34 in contactwith insert 44.

The handle 40 and fastener unit 46 may be formed of any suitable,relatively rigid materials such as metal or a suitable plastic. The plug22 is preferably formed from an inert plastic such as a fluorocarbonhaving cold flow properties, which might be polytetrafluoroethylene orfluorinated ethylene propylene. The insert 44 is an' elastomer such asrubber, or a plastic having rubber-like qualities.

The valve is assembled by inserting handle 40 into handle receivingportion 26 and inserting plug 22 into barrel 10. Due to the taperedconfiguration, the insertion can be made from only one end of thebarrel, from the bottom as seen in FIG. 2. The insert 44 is positionedin recess 34 and the shank of screw 46' is pushed through the insert44which receives it snugly, and threaded into the opening 42 of handle40. As the screw is tightened, the compression shoulder 52 compressesthe elastomeric insert 44 to expand it radially, which exerts radialpressure against plug 24, forcing its relatively flexible centralportion 28 into sealing engagement with the inner surface 16 of barrel10. This tends to insure against fluid leakage but the relatively narrowwidth of central portion 28 also prevents undue friction and permitseasy rotation of the plug without requiring the use of lubricants. Itwill also be apparent from FIG. 2 that the plug is completely axiallyrestrained. The taper prevents upward movement and the screw head 50prevents downward movement.

An alternative construction to that shown, which does not necessitateillustration, might comprise a twopart fastener unit instead of theone-piece unit 46. The handle portion 26 and the handle 40 of the plugmay be structured so as to constitute one piece. The fastener shankcould be secured to the plug, perhaps permanently as an integral partthereof, in any suitable manner and have a threaded part extendingbeyond the walled portion of the plug to receive thereon a nut overlyingand co-acting with the appropriate end of the barrel. The nut could havean axial extension to contact and compress the elastomer insert 44 tothe desired degree to form the aforementioned fluid seal by the selectedadjustment of the nut on the threaded shank. It will be apparent fromthe foregoing that the illustrated fastener unit 46 may be threadedlyadjusted to provide the desired sealing effect between the plug and thebarrel.

With the plug in the illustrated angular position, it will be seen fromFIG. 3 that there is direct communication between the ports 18-, 20.Furthermore, the fluid is contained against the glass wall of barrel land is readily observable. A slight rotation of the plugcounterclockwise, as viewed in FIG. 3, will close off port 18, stoppingall flow. The opposite endof groove 30 terminates in the optionalV-shaped portion 32. Slight rotation in the clockwise direction, asviewed in FIG. 3, reduces the effective cross-section of the groove 30,thereby permitting the valve to function as a metering valve. When theplug is rotated so that the ports 18, 20 are out of communication withone another, the groove 30 in the plug is self-draining.

It will now be apparent that the valve of this invention is extremelycompact and has very few parts. However, all the objectives heretoforeset forth are met in that the valve tends to be fluid tight and has lowfrictional resistance to turning. it will also be apparent to thoseskilled in the art that a number of variations and modifications may bemade in this invention without departing from its spirit and scope.Accordingly, the foregoing description is to be construed asillustrative only rather than limiting. This invention is limited onlyby the scope of the following claims.

What is claimed is:

1. A valve for laboratory glassware comprising: a glass barrel having aconically tapered, smooth, inner surface portion so as to provide alarger inner diameter in proximity to one end of the barrel, at leasttwo side arms integral with said barrel, each defining a fluid passagecommunicating with the interior of the barrel, an inert, deformableplastic plug received through said one end of the barrel and rotatablewithin the barrel, having at least a portion of its outer surfacebearing against said inner surface portion and having a complimentaltaper, said outer surface portion of the plug defining a grooveextending partially. around the circumference thereof to interconnectsaid fluid passageways in an angularly adjusted position of the plug,said plug at one end including a handle portion extending from said oneend of the barrel, and said plug defining an axial recess extending intothe other end of the plug to provide a relatively thin-walled flexiblepart in the area of said outer surface portion, an annular elastomericinsert received in said recess, and fastener means to retain theelements in assembled condition including a member overlying andcoacting with the other barrel end and coacting with a shank in securedrelation to the plug in an axial relationship thereto and extendingthrough said insert, said member having associated therewith acompression part engageable with said insert and being adjustable in andout axially of the plug to vary the compression of the insert, saidinsert on compression expanding said walled portion of the plug intofluid sealing engagement with the barrel.

2. A valve' as defined in claim 1, wherein said member of the fastenerunit is threadedly adjustable axially of the plug.

3. A valve as defined in claim 1, wherein said member of the fastenerunit is angularly fixed to said shank and the latter is threaded into apart in fixed relation to the plug.

4. A valve as defined in claim 1, including a separable handle ofelongated form extending into a bore in said plug handle portionextending transversely of the plug axis, the handle having a threadedtransverse bore, said member of the fastener unit being ang'ularly fixedto said shank, and the latter being threaded into said bore in thehandle.

5. A valve as defined in claim 1, wherein the outer surface bearingportion of the plug has a substantially smaller area than the innersurface of the barrel.

6. A valve as defined in claim 1 wherein the outer surface bearingportion of the plug has a substantially smaller bearing area than saidtapered inner surface portion of the barrel. I

7. A valve as defined in claim 1, wherein said plug groove includes atleast one metering portion in which the cross-sectional area of thegroove varies with the groove length.

8. A valve as defined in claim 1, wherein said plug recess issubstantially cylindrical.

9. A valve as defined in claim 5, wherein said outer surface bearingportion of the plug is substantially midway between the barrel ends.

10. A valve as deflned in claim 7, wherein said metering portioncomprises a tapered end of said groove.

11. A valve for laboratory glassware comprising, a glass barrel having aconically tapered, smooth, inner surface portion so as to provide alarger inner diameter in proximity to one end of the barrel, at leasttwo side arms integral with said barrel, each defining a fluid passagecommunicating with the interior of the barrel,

an inert, deformable plastic plug received through said one end of thebarrel and rotatable within the barrel, having at least the portion ofits outer surface bearing against said inner surface portion and havinga complemental taper, the plug having means defining a fluid channeltherein to interconnect said fluid passageways in an angularly adjustedposition of the plug, said plug at one end including a handle portionextending from said one end of the barrel, and said plug defining an'axial recess extending into the other end of the plug to provide arelatively thin-walled flexible portion in the area of said outersurface portion, an annular

1. A valve for laboratory glassware comprising: a glass barrel having aconically tapered, smooth, inner surface portion so as to provide alarger inner diametEr in proximity to one end of the barrel, at leasttwo side arms integral with said barrel, each defining a fluid passagecommunicating with the interior of the barrel, an inert, deformableplastic plug received through said one end of the barrel and rotatablewithin the barrel, having at least a portion of its outer surfacebearing against said inner surface portion and having a complimentaltaper, said outer surface portion of the plug defining a grooveextending partially around the circumference thereof to interconnectsaid fluid passageways in an angularly adjusted position of the plug,said plug at one end including a handle portion extending from said oneend of the barrel, and said plug defining an axial recess extending intothe other end of the plug to provide a relatively thin-walled flexiblepart in the area of said outer surface portion, an annular elastomericinsert received in said recess, and fastener means to retain theelements in assembled condition including a member overlying andcoacting with the other barrel end and coacting with a shank in securedrelation to the plug in an axial relationship thereto and extendingthrough said insert, said member having associated therewith acompression part engageable with said insert and being adjustable in andout axially of the plug to vary the compression of the insert, saidinsert on compression expanding said walled portion of the plug intofluid sealing engagement with the barrel.
 2. A valve as defined in claim1, wherein said member of the fastener unit is threadedly adjustableaxially of the plug.
 3. A valve as defined in claim 1, wherein saidmember of the fastener unit is angularly fixed to said shank and thelatter is threaded into a part in fixed relation to the plug.
 4. A valveas defined in claim 1, including a separable handle of elongated formextending into a bore in said plug handle portion extending transverselyof the plug axis, the handle having a threaded transverse bore, saidmember of the fastener unit being angularly fixed to said shank, and thelatter being threaded into said bore in the handle.
 5. A valve asdefined in claim 1, wherein the outer surface bearing portion of theplug has a substantially smaller area than the inner surface of thebarrel.
 6. A valve as defined in claim 1 wherein the outer surfacebearing portion of the plug has a substantially smaller bearing areathan said tapered inner surface portion of the barrel.
 7. A valve asdefined in claim 1, wherein said plug groove includes at least onemetering portion in which the cross-sectional area of the groove varieswith the groove length.
 8. A valve as defined in claim 1, wherein saidplug recess is substantially cylindrical.
 9. A valve as defined in claim5, wherein said outer surface bearing portion of the plug issubstantially midway between the barrel ends.
 10. A valve as defined inclaim 7, wherein said metering portion comprises a tapered end of saidgroove.
 11. A valve for laboratory glassware comprising, a glass barrelhaving a conically tapered, smooth, inner surface portion so as toprovide a larger inner diameter in proximity to one end of the barrel,at least two side arms integral with said barrel, each defining a fluidpassage communicating with the interior of the barrel, an inert,deformable plastic plug received through said one end of the barrel androtatable within the barrel, having at least the portion of its outersurface bearing against said inner surface portion and having acomplemental taper, the plug having means defining a fluid channeltherein to interconnect said fluid passageways in an angularly adjustedposition of the plug, said plug at one end including a handle portionextending from said one end of the barrel, and said plug defining anaxial recess extending into the other end of the plug to provide arelatively thin-walled flexible portion in the area of said outersurface portion, an annular elastomeric insert snugly received in saidrecess, and a screw including A threaded elongated shank extendingthrough said insert and threaded into a part in a fixed relation to saidhandle portion, said screw having an enlarged head coacting with theother end of said barrel and carrying a compression part engageable withsaid insert, said insert on compression expanding said flexible wallportion of the plug into sealing engagement with the barrel.